This research presents a u-channel based study of the natural remanent magnetization (NRM), the laboratory magnetization, Anhysteretic Remanent Magnetization (ARM), and magnetic susceptibility (k), from the upper 100 m of International Ocean Discovery Program (IODP) Expedition 383 Site U1543 in the eastern South Pacific sector of the Southern Ocean. Alternating...
This thesis develops a manual for interpreters at six National Park Service areas established to preserve and interpret fossils of the Cenozoic Era: Fossil Butte National Monument (Wyoming), John Day Fossil Beds National Monument (Oregon), Badlands National Park (South Dakota), Florissant Fossil Beds National Monument (Colorado), Agate Fossil Beds National...
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Robert J. Lillie
This thesis develops a manual for interpreters at six National Park Service
Glacial isostatic adjustment (GIA) alters the amplitude and timing of ‘glacioeustatic’ sea level maxima and minima around the globe. No study has examined the intrinsic distance that one can correlate marine stratigraphic records of glacial–interglacial sedimentation across continental shelves subject to varying amounts of GIA. Here, we seek to model...
Rip currents pose a serious danger to visitors of bathing beaches; they are also an important process in surf zone circulation. Haller et al. [2014] demonstrated that shore-based X-band radar can be used to compliment in situ measurements of rip currents. However, little is known of the underlying radar imaging...
Magneto- and chemostratigraphic correlation underpins much of our understanding of Earth history, yet typical correlation techniques are neither quantitative nor objective. Within this dissertation, I detail my efforts to develop and apply dynamic programming-based algorithms that accomplish optimal and reproducible stratigraphic alignment. I apply these algorithms to three geologic intervals:...
Sedimentary records from the North Atlantic, instrumental in the development of modern paleo-geomagnetic concepts, show a highly variable field even during times of constant polarity. Yet, our understanding of how the magnetization is acquired in the sediments is poorly understood. Primary magnetizations preserved in deep-sea sediments are known to be...
This dissertation presents the results of statistical analyses of large climate datasets from two time intervals – the 20th century instrumental record and the proxy record of the last deglaciation – in order to understand the forcings and mechanisms of past climate variability.
A longstanding question in climate dynamics concerns...
Around 74 ka, a supervolcano, Toba Caldera in Sumatra, Indonesia erupted, producing the Youngest Toba Tuff and its associated caldera. After this catastrophic eruption, a lake filled the caldera, sedimentation within the lake occurred, and the process known as resurgence began. Today, the resurgent dome, Samosir Island, is uplifted 700...
This thesis presents the results of an investigation into the measured and modeled
mass balance of the Collier Glacier, a small (0.70 km²), valley glacier located in the
Oregon Cascade Range (44° 10' N, 121° 47' W). Here we present mass-balance
measurements conducted for the 2009 and 2010 balance years...
This dissertation presents results from three studies that address major scientific questions in glacial geology and paleoclimatology for the late Pleistocene and Holocene using relatively new geochemical and statistical techniques. Each of the studies attempts to answer a longstanding question in the respective field using geochemical or statistical methods that...
Use of solid compensators is a very effective means of implementing IMRT on any linear accelerator. The standard practice has been IMRT delivery using accelerators equipped with multi-leaf collimators (MLC’s). Truth is the addition of MLC’s to an accelerator is quite expensive. Previous studies have shown solid compensators to have...
Understanding the relationships between land use, water quality, and groundwater is crucial for ecological, economic, and water management decisions. This study aims to provide a comprehensive analysis of the land use activities and hydrologic processes influencing the water quality of Oak Creek watershed. Objectives of this study were: 1) to...
The hydrologic cycle on Earth comprises the transitions among the solid, liquid, and gaseous phases of water. Understanding the hydrologic cycle is of course important for climate science, but also for agricultural, drinking water, and disaster preparedness purposes. Improvements in satellite observations and general circulation models (GCMs) have led to...
During the Last Glacial Maximum (LGM, ∼ 21 ky before present) the atmospheric CO2 concentration was about 100 ppm lower than its pre-industrial (PI)value. The missing carbon from the atmosphere must have been stored in thedeep ocean during this period, but the mechanisms driving such re-distribution ofthe carbon cycle are...
The goal of dissertation research was to use geochemical, statistical and geological methods to constrain and understand climate variability over several different time scales. Specifically, I have addressed three questions regarding past climate change: (1) how does the record of Irish cirque glaciers constrain the dimensions of the Irish Ice...
This dissertation uses argon geochronology and cosmogenic nuclide surface exposure dating methods to address three research questions. The first question concerns a geomagnetic instability recorded in lava flows on the island of Floreana in the Galapagos Archipelago. Changes in the Earth’s magnetic field (intensity and orientation) occur frequently throughout geologic...
Paleoclimate archives have revealed abrupt climate events that are superimposed on more gradual climate changes throughout the last glacial and deglacial periods. The underlying causes of such rapid climate changes are still poorly understood, but the strong expression of these events in northern hemisphere records likely points to climatic mechanisms...
The deglacial behavior of the sub-Arctic North Pacific is poorly constrained, with many published records suffering from limited age control due to extensive post- depositional biogenic carbonate dissolution. Potential alternative dating methods could include the correlation of stable-isotopic and/or paleomagnetic secular variation records to an independently-dated regional template, however no...
This research investigates the physiological and transcriptional responses of Nitrosomonas europaea when exposed to chlorinated aromatic compounds and heavy metals under varying environmental conditions. It was found that transcriptional responses of identified sentinel genes correlate well with nitrification inhibition. Sorption of metals to biomass was also investigated and found not...
This dissertation presents the results of three studies that assessed climate variability on short and long timescales in western United States. The growth of carbonate formations in caves (speleothems) is used to infer the timing and amplitude of past climate variability. We first assess the controls on speleothem growth for...
The shallow aquifer in Southern Willamette Valley (SWV) has high levels of nitrate, and we are exploring the time trends in nitrate, and the hydrologic and land management factors that contribute to this problem. Nitrogen (N) inputs to farmland from fertilizer is thought to be the primary source of nitrogen...
Forest management is rapidly undergoing a transformation from a discipline based on efficient commodity production to one for multiple uses, especially on federally managed land in the United States. This new management paradigm has challenged silviculturists to develop and adapt forest management techniques that can deal with increased demands. Using...
Rainfall interception is a primary control over the moisture input to a forested ecosystem through the partitioning of precipitation into throughfall, stemflow, and an evaporated component (i.e. the interception loss). Rainfall interception is a spatially and temporally varying process at multiple scales, but heterogeneity in interception processes are poorly understood...
Knowledge of stand structure, stand dynamics, and production ecology of species mixtures lags well behind that of single-species, even-aged stands. Two mixed-species spacing trials in central Oregon allowed investigation of mixed-species dynamics in a controlled experimental setting. The first site, Pringle Butte, is a mixture of ponderosa pine (Pinus ponderosa...
Effect of temperature on seed dormancy, alpha-amylase activity and kernel weight in five wheat (Triticum aestivum L.) varieties was studied. Three ripening temperature conditions - 15.5°C, 26.6 °C and "Field" were used to induce dormancy. Alpha-amylase activity and kernel weight of developing kernels was determined every ten days after anthesis...
Climate change impacts everyone’s food and water security. Increasing global temperatures accelerate the hydrologic cycle and consequently impact the water resources for billions of people worldwide. Countless models have been developed to represent various components of the hydrologic cycle at various spatial and temporal scales. These are often validated against...
Quaking aspen (Populus tremuloides Michx) is a species with high phenotypic plasticity and a broad distribution that, in the last decade, has experienced climate stress-induced mortality called Sudden Aspen Decline (SAD). In order to help mitigate the effects of SAD in the future, we need a better understanding of aspen’s...
The links between forests, streamflow, and climate are poorly understood. Despite hundreds of studies over the past 60 years, fundamental questions of forests' effects on the hydrologic cycle remain unanswered. The hydrological cycle involves mutually-dependent biological and physical processes that operate at multiple scales of time and space, and this...
This thesis builds on a modeling tool that has been developed to link thermodynamic modeling and concrete performance. This tool is intended to predict the performance for modern concrete mixtures made with ordinary portland cement (OPC), conventional and novel supplementary cementitious materials (SCMs), and limestone (Ls). The first part of...
Earthquake engineering analyses are often performed using shallow, crustal earthquake motions (e.g., 1940 El Centro). However, large areas of the world are subject to subduction zone earthquake motions (e.g., the Pacific Northwest). A subduction zone earthquake motion is characterized by its long duration (e.g., strong shaking lasts for more than...
The basic objective of this thesis was to estimate the
economic effects of yield grade standards for carcass beef
on the various market sectors of the Canadian beef industry.
The adoption of the standards was expected to enhance
consumer demand, improve efficiency within the processing
and marketing services sectors, and...
The knowledge about the intensive agricultural irrigation is very limited, but the use of irrigation is rapidly increasing. As an outcome, the sympathetic ecosystem is accepting modern irrigation that will play an essential function in the present and future for agricultural products. My dissertation will display the modification for investigation...
It is uncertain how predicted changes in climate will impact vegetation responses and plant species’ distributions because the physiological mechanisms underlying thresholds for damage are not well understood, and responses to stress vary by functional type and developmental stage. Thus, it is crucial to investigate physiological responses to heat and...
Teacher noticing is a necessary skill in order for teachers to elicit and respond to their
students' mathematical ideas and support the ambitious learning goals of school mathematics. The purpose of this dissertation is to investigate what teacher candidates noticed about their teaching as they were provided supports and opportunities...
This dissertation integrates a process-based hydrological investigation with an
ongoing paired-catchment study to better understand how forest harvest impacts
catchment function at multiple scales. We do this by addressing fundamental questions
related to the stocks, flows and transit times of water. Isotope tracers are used within a
top-down catchment intercomparison...
The main objective of this study was to offer an alternative methodology for
forest sector modeling in developing economies. To this effect, a policy preference
function was developed and estimated using data from the forest sector of the Cote
d'Ivoire.
The justification for this alternative framework for forest sector analysis...
The purpose of this study was to compare the self-perceived
leadership styles, range and adaptability of
women managers in higher education and non-education management positions. Specifically, the study sought to
investigate the: (1) self-perceived leadership styles and
adaptability of women managers in higher education and non-education,
(2) self-perceived leadership styles...
The purposes of this phenomenological inquiry was to examine the challenges faced by administrative leaders of Disabled Student Programs and Services (DSPS) at California community colleges (CCC) from the perspectives of current practitioners. This study was undertaken for the following reasons: (a) the increasing number of students with disabilities accessing...
The validation and potential use of mathematical models to estimate the
shelf-life of refrigerated food exposed to temperature abuse and basing such
estimations on microbial growth was analyzed. Combined heat transfer, microbial
growth models, and non-parametric statistical procedures formed a computer-based
predictive tool to assess shelf-life and estimate the accuracy...
Community colleges in the United States have become an important educational destination for international students. According to the Institute of International Education (IIE, 2006), international students who enrolled for the first time at a U.S. campus increased by 8 per cent, from 131,946 students in 2004/2005 to 142,923 in 2005/2006....
Decision-making is a highly complex process influenced by the values, attitudes, and cognitive biases of the decision-maker. The classical model of decision-making fails to fully incorporate how decisions are made in situations of uncertainty, where having complete knowledge of all possible outcomes and alternatives is not always possible. In highly...
To study the association between Fusarium root-rot resistance
(Fusarium solani f. sp. phaseoli) and economically inportant characteristics
of beans, 2259 lines each consisting of 30 plants were used.
The lines were randomly selected for root-rot reaction, but were
selected for differences in vigor and differences in plant and seed
pigments,...
The identification and mapping of surface cover types
within Crater Lake National Park, Oregon, has been effectively
completed through the utilization of LANDSAT digital
data and NASA U-2 color infrared aerial photography. Classification
of LANDSAT data for surface cover type identification
and mapping was accomplished through use of the
Interactive...
The feasibility of utilizing LANDSAT MSS data in assessing surface cover types and areal extent of clearcut and shelterwood cut harvest sites in southern Oregon was investigated. The research utilized extensive 'ground truth' information to evaluate the LANDSAT data. A three faceted ground truth collection scheme analyzed 1) U.S. Forest...
Six parent clones and their 15 single-crosses of tall fescue (Festuca arundinaceae, Schreb) were row-planted in Corvallis, Oregon, row and sward-planted in Columbia, Missouri, and evaluated for genetic variability, genotyp-eenvironment interactions and interrelationships in acid detergent fiber (ADF), neutral detergent fiber (NDF), hemicellulose (HCL), crude protein (CP) and in vitro...
The purpose of this study was to seek evidence which might
lead to the development of more effective ways of dealing with the
problem of failure to attend school.
Concept of self has long been considered worthy of consideration
in evaluating behavior. It is known that significant experiences
in life...
The main purpose of this study was to investigate and describe strategies that Thai ninth grade students use to solve algebra word problems. The second purpose of this study was to investigate teachers' instruction during word problem solving lessons. Three mathematics teachers and one of each of their classes participated...